Method of removing tarnish from metals.



WE, W 7

' M. H. KEYT. METHOD OF REMOVING TARNISH mom METALS.

I APPLIOATION FILED NOV. 12, 1908.

937,154, Patented Oct; 19, 1909.

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Man 52 421.11. r

of soda, and sodium. sulfate.

, MET-iron or Rumor me TARNISH FROM METALS.

To all whom it may concem: I

Be it known that I, hlARSHALL H. KEYT, a citizen of the United States of America, re-

siding at Chicago, in the county of Cook.

and State of Illinois,'have invented certain new and useful Improvements in Methods of Removing Tarnish from Metals, of which forth.

Primarily, the method consists in immersing the metal from which the tarnish is to be removed in an electrolytein which is im-' mersed a metal of .a more positive electrical character. The method is applicable in brightening all kinds of metals, but for the purpose of illustration it Will be described in the removal of tarnish from silver.

The invention further consists in a novel construction of apparatus for carrying out the method.

In the draWings,F-igures l and 2 represent apparatus suitable for carrying out the steps of the process, Fig. 1 being a sectional perspective view and Fig. 2a modified form of apparatus.

a receptacle of any suitable type,- and B a metal plate or sheet therein, the metal being.

preferably zinc.

' C designates the electrolyte, a solution containing carbonate of soda, bicarbonate The preferred proportions of the ingredients are: two parts, by weight,'. of the carbonate; two parts of thebicarbonateyand one part of the sulfate. These ingredients are intimately mixed and preferably oured into. .the water? Within the receptac e forming the solution, the water being preferably at the boiling point to produce the best results. The silver or other metal to be brightened is immersed in the electrolyte, and the tarnish disappears in practice' veryshortly after the immersion is effected, inmost instances merely a dipping of the article being required; As understood, an electrolytic act ras an @FFEQE.

' jplraits irntn*iixfigur'r, or (intense, ILLINois.

:3 Specification of lietters'rateiit; Application filed November 12, 1908. Serial No. 462,295.

' Patented Get. 19, race.

Within the bath. To obtain satisfactory resuits it is essential that the tarnish upon the metal having the higher-positive electrical characteristics be removed andthe metal k ept bright during the carrying out of. the method.

In Fig. 2 a'niodilied form of apparatus is illustrated-especially designed for use i=3. ren'ioving the tarnish from silverware, such as knives, forks, and-the like. It comprises a receptacle D, made entirely of zinc, and a holder for the articles or utensils E in, the

form of a U-shaped tray, the major portion I gut. the necessity of the hands of the operator eing' placed within the electrolyte. As previously pointed out, the method may be carried out in brightening metals of all kinds, and it is to be understood that other. metals than 'zinc may be employed as the constantly-immersed electrode. Zinc is Y preferable, however, as the reaction is more The reference-letter A (Fig. 1) designates rapid, with theresultthat the time required for carrying out the processis reduced to'a minimum.

Attention is further. directed to the fact that whereas the electrolytic action will take place upon merely dipping the metal to be brightened within theelectrolyte, the operation is materially hastened by bringing the tarnished metal into direct contact with the positive electrode after immersion. The construction of apparatus shown in Fig. 2 of the drawings is especially applicable for this purpose, the articles being adapted to contact directly with the zinc tray, or may contactone with another and finally with a tray.

Iam aware that soda salts have been employed heretofore as the active agent of an electrolyte, but the particular combination of salts set forthaboveis 'believed to be novel and superior to any other" composition heretofore used in that it. is capable of effecting a rapid reaction, and the electrolyte remains active for a maximum period of time.

What I claim as my invention is,-

the metalto be brightened in an electrolyte consisting of sodium carbonate, sodium bi f The herein-described process for removing electrical contact with the more positive tarnlsh from metals, cons1st1ng 1n lmmerslng metal. 10

In testimony whereof I aflix my signature in presence of two Witnesses.

carbonate, and sodium sulfate, in solution, MARSHALL H. KEYT.

in which is immerseda metal of a more posi- Witnesses: tive electrical character, and in bringing the NELLIE KINsELLA,

metal 'to be brightened after immersion into I HARRY W. GALVIl\. 

